On 8 August 2026, the Rhine at Basel recorded its lowest daily discharge since 2020, with a mean flow of 428 m³/s that made August 2026 the month with the lowest minimum average flow on record. These low water levels have far-reaching consequences, including sharply higher transport costs, degraded water quality, restrictions on cooling water use, and pressure on irrigation and groundwater supplies.
On 8 August 2026, the average daily discharge of the Rhine at Basel-Kleinhüningen was lower than 1% of all daily values recorded since 2020. The flow ranged from a minimum of 319 m³/s to a maximum of 499 m³/s, with a mean of 428 m³/s. These values are not notably high; the maximum discharge ranked 31st over the last 30 days, the lowest of any August day since 2020, and the lowest of any day in the entire record since 2020.
Over the past 30 days, the highest discharge was 710 m³/s on 19 July 2026, while the lowest was 321 m³/s on 2 August 2026. Table 2 lists the months with the lowest flow conditions since 2020, and August 2026 now tops that list with a minimum average flow of 428 m³/s, surpassing the previous low of 436 m³/s set in August 2022.
Low water levels on the Rhine have consequences that reach well beyond the river itself. Cargo vessels have to reduce their load to stay clear of the riverbed, so more trips are needed to move the same volume and transport costs rise sharply, with the effect passed on to industries that depend on the waterway for coal, oil products, chemicals and grain. The shallower water also heats up faster in summer. Warmer water encourages bacterial growth, which can produce noticeable odors, and it holds less dissolved oxygen. The combination of higher temperatures, lower oxygen and more concentrated pollutants degrades water quality and can lead to fish kills. Swimming is generally discouraged under these conditions because of the higher bacterial load. Further effects include restrictions on power plants and industrial sites that draw river water for cooling, since they may no longer discharge warmed water without exceeding temperature limits, reduced dilution of treated wastewater, pressure on water supply and irrigation in the surrounding area, and falling groundwater levels along the river that affect riparian vegetation and wells.
| metric | '2026-08-08'::date | Historic |
|---|---|---|
| Average discharge | 428.0 | 1029.7 |
| Maximum discharge | 499.3 | 2834.5 |
| Minimum discharge | 318.8 | 259.9 |
| Month | Min Avg Flow [m3/s] |
|---|---|
| 08.2026 | 428.0 |
| 08.2022 | 435.9 |
| 07.2026 | 442.1 |
| 04.2025 | 470.4 |
| 03.2023 | 471.4 |
🤖 This text was generated with the assistance of AI. All quantitative statements are derived directly from the dataset listed under Data Source.